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Hull JJ, Heu CC, Gross RJ, LeRoy DM, Schutze IX, Langhorst D, Fabrick JA, Brent CS. Doublesex is essential for masculinization but not feminization in Lygus hesperus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2024; 166:104085. [PMID: 38307215 DOI: 10.1016/j.ibmb.2024.104085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 01/12/2024] [Accepted: 01/24/2024] [Indexed: 02/04/2024]
Abstract
In most holometabolous insects, sex differentiation occurs via a hierarchical cascade of transcription factors, with doublesex (dsx) regulating genes that control sex-specific traits. Although less is known in hemimetabolous insects, early evidence suggests that substantial differences exist from more evolutionarily advanced insects. Here, we identified and characterized dsx in Lygus hesperus (western tarnished plant bug), a hemipteran pest of many agricultural crops in western North America. The full-length transcript for L. hesperus dsx (Lhdsx) and several variants encode proteins with conserved DNA binding and oligomerization domains. Transcript profiling revealed that Lhdsx is ubiquitously expressed, likely undergoes alternative pre-mRNA splicing, and, unlike several model insects, is sex-biased rather than sex-specific. Embryonic RNA interference (RNAi) of Lhdsx only impacted sex development in adult males, which lacked both internal reproductive organs and external genitalia. No discernible impacts on adult female development or reproductivity were observed. RNAi knockdown of Lhdsx in nymphs likewise only affected adult males, which lacked the characteristic dimorphic coloration but had dramatically elevated vitellogenin transcripts. Gene knockout of Lhdsx by CRISPR/Cas9 editing yielded only females in G0 and strongly biased heterozygous G1 offspring to females with the few surviving males showing severely impaired genital development. These results indicate that L. hesperus male development requires Lhdsx, whereas female development proceeds via a basal pathway that functions independently of dsx. A fundamental understanding of sex differentiation in L. hesperus could be important for future gene-based management strategies of this important agricultural pest.
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Affiliation(s)
- J Joe Hull
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA.
| | - Chan C Heu
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Roni J Gross
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Dannialle M LeRoy
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Inana X Schutze
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Daniel Langhorst
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Jeffrey A Fabrick
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - Colin S Brent
- USDA ARS, U.S. Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
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2
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Liao J, Wan H, Zhang Z, Sheng Y, Jia X, Wang Y. Transcriptional regulation of IAG by dsx and foxl-2 in mud crab (Scylla paramamosain). Gen Comp Endocrinol 2024; 345:114396. [PMID: 37879419 DOI: 10.1016/j.ygcen.2023.114396] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 10/07/2023] [Accepted: 10/21/2023] [Indexed: 10/27/2023]
Abstract
Scylla paramamosain is an important cultured crab species on the southeast coast of China. However, the molecular regulation mechanism of its gonadal development still has not been thoroughly studied. Dsx (doublesex) and foxl-2 (forkhead transcription factor gene 2) are important transcription factors involved in gonadal development. So far, studies on the functions of dsx and foxl-2 in crustaceans are very limited. Insulin-like androgenic gland hormone (IAG) is an effector molecule that regulates the differentiation, development and sex maintenance of testes in crustaceans. In this study, the promoter region of Sp-IAG was predicted, and several potential binding sites of dsx and foxl-2 were found. Site-directed mutagenesis was performed on the predicted potential binding sites, and their promoter activity was analyzed. The results showed that there was a dsx and a foxl-2 binding site, respectively, that could regulate the expression of Sp-IAG. In order to verify the regulatory effect of these two transcription factors on Sp-IAG, we constructed the expression plasmids of dsx and foxl-2 and co-transfected them into HEK293T cell lines with the promoter of Sp-IAG, respectively. The results showed that dsx could significantly promote the expression of Sp-IAG, while foxl-2 could inhibit its expression substantially. Then we carried out in vivo RNA interference experiment on mud crabs. The expression of dsx and foxl-2 in crabs was interfered respectively. The results of qRT-PCR showed that the expression of Sp-IAG was significantly inhibited after interfering with dsx, while significantly increased after interfering with foxl-2, which was consistent with the cell experiment. In conclusion, dsx and foxl-2 transcription factors play opposite roles in regulating the expression of Sp-IAG.
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Affiliation(s)
- Jiaqian Liao
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China; Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Xiamen 361021, China
| | - Haifu Wan
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China; Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Xiamen 361021, China
| | - Ziping Zhang
- College of Marine Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yinshen Sheng
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China; Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Xiamen 361021, China
| | - Xiwei Jia
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China; Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Xiamen 361021, China
| | - Yilei Wang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China; Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Xiamen 361021, China.
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3
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VanKuren NW, Doellman MM, Sheikh SI, Palmer Droguett DH, Massardo D, Kronforst MR. Acute and Long-Term Consequences of Co-opted doublesex on the Development of Mimetic Butterfly Color Patterns. Mol Biol Evol 2023; 40:msad196. [PMID: 37668300 PMCID: PMC10498343 DOI: 10.1093/molbev/msad196] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 09/06/2023] Open
Abstract
Novel phenotypes are increasingly recognized to have evolved by co-option of conserved genes into new developmental contexts, yet the process by which co-opted genes modify existing developmental programs remains obscure. Here, we provide insight into this process by characterizing the role of co-opted doublesex in butterfly wing color pattern development. dsx is the master regulator of insect sex differentiation but has been co-opted to control the switch between discrete nonmimetic and mimetic patterns in Papilio alphenor and its relatives through the evolution of novel mimetic alleles. We found dynamic spatial and temporal expression pattern differences between mimetic and nonmimetic butterflies throughout wing development. A mimetic color pattern program is switched on by a pulse of dsx expression in early pupal development that causes acute and long-term differential gene expression, particularly in Wnt and Hedgehog signaling pathways. RNAi suggested opposing, novel roles for these pathways in mimetic pattern development. Importantly, Dsx co-option caused Engrailed, a primary target of Hedgehog signaling, to gain a novel expression domain early in pupal wing development that is propagated through mid-pupal development to specify novel mimetic patterns despite becoming decoupled from Dsx expression itself. Altogether, our findings provide multiple views into how co-opted genes can both cause and elicit changes to conserved networks and pathways to result in development of novel, adaptive phenotypes.
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Affiliation(s)
- Nicholas W VanKuren
- Department of Ecology & Evolution, The University of Chicago, Chicago, IL, USA
| | - Meredith M Doellman
- Department of Ecology & Evolution, The University of Chicago, Chicago, IL, USA
| | - Sofia I Sheikh
- Department of Ecology & Evolution, The University of Chicago, Chicago, IL, USA
| | | | - Darli Massardo
- Department of Ecology & Evolution, The University of Chicago, Chicago, IL, USA
| | - Marcus R Kronforst
- Department of Ecology & Evolution, The University of Chicago, Chicago, IL, USA
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4
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Tunström K, Woronik A, Hanly JJ, Rastas P, Chichvarkhin A, Warren AD, Kawahara AY, Schoville SD, Ficarrotta V, Porter AH, Watt WB, Martin A, Wheat CW. Evidence for a single, ancient origin of a genus-wide alternative life history strategy. SCIENCE ADVANCES 2023; 9:eabq3713. [PMID: 36947619 PMCID: PMC10032607 DOI: 10.1126/sciadv.abq3713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Understanding the evolutionary origins and factors maintaining alternative life history strategies (ALHS) within species is a major goal of evolutionary research. While alternative alleles causing discrete ALHS are expected to purge or fix over time, one-third of the ~90 species of Colias butterflies are polymorphic for a female-limited ALHS called Alba. Whether Alba arose once, evolved in parallel, or has been exchanged among taxa is currently unknown. Using comparative genome-wide association study (GWAS) and population genomic analyses, we placed the genetic basis of Alba in time-calibrated phylogenomic framework, revealing that Alba evolved once near the base of the genus and has been subsequently maintained via introgression and balancing selection. CRISPR-Cas9 mutagenesis was then used to verify a putative cis-regulatory region of Alba, which we identified using phylogenetic foot printing. We hypothesize that this cis-regulatory region acts as a modular enhancer for the induction of the Alba ALHS, which has likely facilitated its long evolutionary persistence.
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Affiliation(s)
- Kalle Tunström
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Alyssa Woronik
- Department of Zoology, Stockholm University, Stockholm, Sweden
- Department of Biology, Sacred Heart University, Fairfield, CT, USA
| | - Joseph J. Hanly
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Pasi Rastas
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Anton Chichvarkhin
- National Scientific Center of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Palchevskogo 17, Vladivostok 690022, Russia
| | - Andrew D. Warren
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Akito Y. Kawahara
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Sean D. Schoville
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - Vincent Ficarrotta
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Adam H. Porter
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Ward B. Watt
- Department of Biology, University of South Carolina, Columbia, SC 29208, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
| | - Arnaud Martin
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
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5
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Komata S, Yoda S, KonDo Y, Shinozaki S, Tamai K, Fujiwara H. Functional unit of supergene in female-limited Batesian mimicry of Papilio polytes. Genetics 2023; 223:iyac177. [PMID: 36454671 PMCID: PMC9910408 DOI: 10.1093/genetics/iyac177] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 12/05/2022] Open
Abstract
Supergenes are sets of genes and genetic elements that are inherited like a single gene and control complex adaptive traits, but their functional roles and units are poorly understood. In Papilio polytes, female-limited Batesian mimicry is thought to be regulated by a ∼130 kb inversion region (highly diversified region: HDR) containing 3 genes, UXT, U3X, and doublesex (dsx) which switches non-mimetic and mimetic types. To determine the functional unit, we here performed electroporation-mediated RNAi analyses (and further Crispr/Cas9 for UXT) of genes within and flanking the HDR in pupal hindwings. We first clarified that non-mimetic dsx-h had a function to form the non-mimetic trait in female and only dsx-H isoform 3 had an important function in the formation of mimetic traits. Next, we found that UXT was involved in making mimetic-type pale-yellow spots and adjacent gene sir2 in making red spots in hindwings, both of which refine more elaborate mimicry. Furthermore, downstream gene networks of dsx, U3X, and UXT screened by RNA sequencing showed that U3X upregulated dsx-H expression and repressed UXT expression. These findings demonstrate that a set of multiple genes, not only inside but also flanking HDR, can function as supergene members, which extends the definition of supergene unit than we considered before. Also, our results indicate that dsx functions as the switching gene and some other genes such as UXT and sir2 within the supergene unit work as the modifier gene.
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Affiliation(s)
- Shinya Komata
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Shinichi Yoda
- NIBB Core Research Facilities, National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Yûsuke KonDo
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Souta Shinozaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Kouki Tamai
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Haruhiko Fujiwara
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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Just J, Laslo M, Lee YJ, Yarnell M, Zhang Z, Angelini DR. Distinct developmental mechanisms influence sexual dimorphisms in the milkweed bug Oncopeltus fasciatus. Proc Biol Sci 2023; 290:20222083. [PMID: 36722087 PMCID: PMC9890105 DOI: 10.1098/rspb.2022.2083] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/10/2023] [Indexed: 02/02/2023] Open
Abstract
Sexual dimorphism is common in animals. The most complete model of sex determination comes from Drosophila melanogaster, where the relative dosage of autosomes and X chromosomes leads indirectly to sex-specific transcripts of doublesex (dsx). Female Dsx interacts with a mediator complex protein encoded by intersex (ix) to activate female development. In males, the transcription factor encoded by fruitless (fru) promotes male-specific behaviour. The genetics of sex determination have been examined in a small number of other insects, yet several questions remain about the plesiomorphic state. Is dsx required for female and male development? Is fru conserved in male behaviour or morphology? Are other components such as ix functionally conserved? To address these questions, we report expression and functional tests of dsx, ix and fru in the hemipteran Oncopeltus fasciatus, characterizing three sexual dimorphisms. dsx prevents ix phenotypes in all sexes and dimorphic traits in the milkweed bug. ix and fru are expressed across the body, in females and males. fru and ix also affect the genitalia of both sexes, but have effects limited to different dimorphic structures in different sexes. These results reveal roles for ix and fru distinct from other insects, and demonstrate distinct development mechanisms in different sexually dimorphic structures.
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Affiliation(s)
- Josefine Just
- Department of Biology, Colby College, 5700 Mayflower Hill, Waterville, ME 04901, USA
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA
| | - Mara Laslo
- Curriculum Fellows Program, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Ye Jin Lee
- Department of Biology, Colby College, 5700 Mayflower Hill, Waterville, ME 04901, USA
| | - Michael Yarnell
- Department of Pediatrics, University of Colorado School of Medicine, 13123 East 16th Avenue, B065, Aurora, CO 80045, USA
| | - Zhuofan Zhang
- School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive, Atlanta, GA 30332, USA
| | - David R. Angelini
- Department of Biology, Colby College, 5700 Mayflower Hill, Waterville, ME 04901, USA
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7
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Komata S, Kajitani R, Itoh T, Fujiwara H. Genomic architecture and functional unit of mimicry supergene in female limited Batesian mimic Papilio butterflies. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210198. [PMID: 35694751 PMCID: PMC9189499 DOI: 10.1098/rstb.2021.0198] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/17/2022] [Indexed: 11/12/2022] Open
Abstract
It has long been suggested that dimorphic female-limited Batesian mimicry of two closely related Papilio butterflies, Papilio memnon and Papilio polytes, is controlled by supergenes. Whole-genome sequencing, genome-wide association studies and functional analyses have recently identified mimicry supergenes, including the doublesex (dsx) gene. Although supergenes of both the species are composed of highly divergent regions between mimetic and non-mimetic alleles and are located at the same chromosomal locus, they show critical differences in genomic architecture, particularly with or without an inversion: P. polytes has an inversion, but P. memnon does not. This review introduces and compares the detailed genomic structure of mimicry supergenes in two Papilio species, including gene composition, repetitive sequence composition, breakpoint/boundary site structure, chromosomal inversion and linkage disequilibrium. Expression patterns and functional analyses of the respective genes within or flanking the supergene suggest that dsx and other genes are involved in mimetic traits. In addition, structural comparison of the corresponding region for the mimicry supergene among further Papilio species suggests three scenarios for the evolution of the mimicry supergene between the two Papilio species. The structural features revealed in the Papilio mimicry supergene provide insight into the formation, maintenance and evolution of supergenes. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
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Affiliation(s)
- Shinya Komata
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Rei Kajitani
- School of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan
| | - Takehiko Itoh
- School of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan
| | - Haruhiko Fujiwara
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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8
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Shimajiri T, Otaki JM. Phenotypic Plasticity of the Mimetic Swallowtail Butterfly Papilio polytes: Color Pattern Modifications and Their Implications in Mimicry Evolution. INSECTS 2022; 13:insects13070649. [PMID: 35886825 PMCID: PMC9322193 DOI: 10.3390/insects13070649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/05/2022] [Accepted: 07/16/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary Diverse butterfly wing color patterns are evolutionary products in response to environmental changes in the past. Environmental stress, such as temperature shock, is known to induce color pattern modifications in various butterfly species, and this phenotypic plasticity plays an important role in color pattern evolution. However, the potential contributions of phenotypic plasticity to mimicry evolution have not been evaluated. Here, we focused on the swallowtail butterfly Papilio polytes, which has nonmimetic and mimetic forms in females, to examine its plastic phenotypes. Cold shock and heat shock treatments in the nonmimetic form induced color pattern modifications that were partly similar to those of the mimetic form, and nonmimetic females were more sensitive than males and mimetic females. These results suggest that phenotypic plasticity in nonmimetic females might have provided a basis of natural selection for mimetic color patterns during evolution. Abstract Butterfly wing color patterns are sensitive to environmental stress, such as temperature shock, and this phenotypic plasticity plays an important role in color pattern evolution. However, the potential contributions of phenotypic plasticity to mimicry evolution have not been evaluated. Here, we focused on the swallowtail butterfly Papilio polytes, which has nonmimetic and mimetic forms in females, to examine its plastic phenotypes. In the nonmimetic form, medial white spots and submarginal reddish spots in the ventral hindwings were enlarged by cold shock but were mostly reduced in size by heat shock. These temperature-shock-induced color pattern modifications were partly similar to mimetic color patterns, and nonmimetic females were more sensitive than males and mimetic females. Unexpectedly, injection of tungstate, a known modification inducer in nymphalid and lycaenid butterflies, did not induce any modification, but fluorescent brightener 28, another inducer discovered recently, induced unique modifications. These results suggest that phenotypic plasticity in nonmimetic females might have provided a basis of natural selection for mimetic color patterns during evolution.
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Steward RA, de Jong MA, Oostra V, Wheat CW. Alternative splicing in seasonal plasticity and the potential for adaptation to environmental change. Nat Commun 2022; 13:755. [PMID: 35136048 PMCID: PMC8825856 DOI: 10.1038/s41467-022-28306-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 01/19/2022] [Indexed: 12/15/2022] Open
Abstract
Seasonal plasticity is accomplished via tightly regulated developmental cascades that translate environmental cues into trait changes. Little is known about how alternative splicing and other posttranscriptional molecular mechanisms contribute to plasticity or how these mechanisms impact how plasticity evolves. Here, we use transcriptomic and genomic data from the butterfly Bicyclus anynana, a model system for seasonal plasticity, to compare the extent of differential expression and splicing and test how these axes of transcriptional plasticity differ in their potential for evolutionary change. Between seasonal morphs, we find that differential splicing affects a smaller but functionally unique set of genes compared to differential expression. Further, we find strong support for the novel hypothesis that spliced genes are more susceptible than differentially expressed genes to erosion of genetic variation due to selection on seasonal plasticity. Our results suggest that splicing plasticity is especially likely to experience genetic constraints that could affect the potential of wild populations to respond to rapidly changing environments.
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Affiliation(s)
| | | | - Vicencio Oostra
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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10
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Rodriguez-Caro F, Fenner J, Bhardwaj S, Cole J, Benson C, Colombara AM, Papa R, Brown MW, Martin A, Range RC, Counterman BA. Novel doublesex duplication associated with sexually dimorphic development of dogface butterfly wings. Mol Biol Evol 2021; 38:5021-5033. [PMID: 34323995 PMCID: PMC8557438 DOI: 10.1093/molbev/msab228] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Sexually dimorphic development is responsible for some of the most remarkable phenotypic variation found in nature. Alternative splicing of the transcription factor gene doublesex (dsx) is a highly conserved developmental switch controlling the expression of sex-specific pathways. Here, we leverage sex-specific differences in butterfly wing color pattern to characterize the genetic basis of sexually dimorphic development. We use RNA-seq, immunolocalization, and motif binding site analysis to test specific predictions about the role of dsx in the development of structurally based ultraviolet (UV) wing patterns in Zerene cesonia (Southern Dogface). Unexpectedly, we discover a novel duplication of dsx that shows a sex-specific burst of expression associated with the sexually dimorphic UV coloration. The derived copy consists of a single exon that encodes a DNA binding but no protein-binding domain and has experienced rapid amino-acid divergence. We propose the novel dsx paralog may suppress UV scale differentiation in females, which is supported by an excess of Dsx-binding sites at cytoskeletal and chitin-related genes with sex-biased expression. These findings illustrate the molecular flexibility of the dsx gene in mediating the differentiation of secondary sexual characteristics.
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Affiliation(s)
| | | | | | - Jared Cole
- Department of Integrative Biology, University of Texas, Austin, USA
| | - Caleb Benson
- Department of Biological Sciences, Auburn University, USA
| | | | - Riccardo Papa
- Department of Biological Sciences, University of Puerto Rico-Rio Piedras, USA
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, USA
| | - Arnaud Martin
- Department of Biological Sciences, The George Washington University, USA
| | - Ryan C Range
- Department of Biological Sciences, Auburn University, USA
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